JP2023001419A - Heat exchanger and refrigeration system using the same - Google Patents

Abstract

To provide a heat exchanger having an improved heat exchange performance and a refrigeration system using the heat exchanger.SOLUTION: A heat exchanger includes: an end plate 3a having an opening 14 serving as an inlet/outlet of fluid; and connection piping A4 connected to a header flow passage opening of the end plate. The connection piping is formed of a bent pipe. A pipe expansion part 15 with a bead 16 is provided on the header flow passage opening side of the end plate, and the pipe expansion part 15 is fitted and joined to the opening 14 of the end plate 3a. This configuration can improve a heat exchange performance, and secure and reduce labor and time for brazing for joining the connection piping to the end plate and joining system piping to the connection piping. Accordingly, the inexpensive, highly reliable and sophisticated heat exchanger and a refrigeration system using the heat exchanger can be provided.SELECTED DRAWING: Figure 5

Description

TECHNICAL FIELD The present invention relates to a heat exchanger and a refrigeration system using the same, and more particularly to a structure for connecting sleeves and connecting pipes provided at the entrance and exit of a plate fin laminate type heat exchanger constructed by stacking plate fins. .

Patent Literature 1 discloses a plate-fin laminated heat exchanger. This laminated plate-fin heat exchanger is constructed by laminating a plurality of plate fins each having a pair of header channels and heat transfer channels. As shown in FIG. 10, in the header flow path 101, a sleeve serving as an inflow/outflow pipe is inserted into the header flow path opening 104 serving as a fluid inlet/outlet of the end plate 103 arranged on the outermost side of the plate fins 102. A connection pipe 106 is joined to each sleeve 105 and brazed to the system pipe on the refrigeration system side. In the plate fin laminated heat exchanger having the above configuration, a first fluid such as a refrigerant flowing from the connecting pipe 106 to the heat transfer channel (not shown) through the header channel 101 and the plate fins 102 are in contact with each other. Heat is exchanged with a second fluid such as air flowing through the gap.

JP 2018-66531 A

The present disclosure provides a heat exchanger and a refrigeration system using the same that solves the problem caused by the joining configuration of the connecting pipes and improves heat exchange performance and reliability.

A heat exchanger according to the present disclosure includes an end plate having an opening serving as a fluid inlet and outlet, and a connection pipe connected to the opening of the end plate. The connection pipe is formed of a bent pipe, and the end plate An enlarged tube portion with a bead is provided on the opening side, and the enlarged tube portion is fitted and joined to the opening of the end plate.

The heat exchanger according to the present disclosure has the above configuration, which reduces the protrusion of the connecting pipes to increase the area of the entire heat exchanger, and the flow deceleration effect of the expanded pipe portion provided in the connecting pipes. Uniformity of fluid distribution can be promoted to improve heat exchange performance. In addition, the connecting pipe and the end plate can be joined by furnace brazing, which requires less man-hours for brazing, and the connecting pipe and the system pipe can be securely and firmly brazed by reducing heat loss, etc. that occurs during torch brazing. can be performed, and an inexpensive, highly reliable, high-performance heat exchanger and a refrigeration system using the same can be obtained.

1 is a perspective view showing the appearance of the plate-fin laminated heat exchanger according to Embodiment 1. FIG. Disassembled perspective view of the same plate-fin laminated heat exchanger FIG. 2 is a perspective view showing a laminated state of plate fin laminates of the same plate fin laminate type heat exchanger. A plan view showing plate fins of the same plate-fin laminated heat exchanger. Cross-sectional view showing the connecting pipe joint configuration of the same plate-fin laminated heat exchanger Cross-sectional view of end plates and connecting pipes of the same plate-fin laminated heat exchanger Explanatory drawing showing a bead forming method of the same plate-fin laminated heat exchanger A refrigeration cycle diagram of an air conditioner as an example of a refrigeration system using the same plate-fin laminated heat exchanger. Sectional view showing the indoor unit of the same air conditioner Schematic diagram for explaining the connection pipe joint configuration of the plate fin laminated heat exchanger before the present disclosure Schematic diagram for explaining the problem of the plate-fin laminated heat exchanger before reaching the present disclosure

(Knowledge, etc. on which this disclosure is based)
At the time when the inventors came up with the present disclosure, a heat exchanger such as a plate fin laminated heat exchanger had a header flow path of the end plate 103 arranged at the outermost side of the plate fins 102 as described above. A sleeve 105 is provided in the opening 104 for connection, and the connection pipe 106 is joined by brazing. Therefore, it is necessary to reduce the total area of the heat exchanger by reducing the number of laminated plate fins by the amount of protrusion L of the connection pipe 106. There was a problem that it was necessary to increase the area and improve the heat exchange performance.

In addition to improving the heat exchange performance, the plate fin laminate type heat exchanger uses a refrigerant as a fluid and is installed so that the header flow path 101 is horizontal. Due to the difference in inertial force of the gas-liquid two-phase refrigerant flowing into the heat exchanger, the gas-liquid two-phase refrigerant tends to separate from the liquid phase refrigerant in the main body of the heat exchanger. There were also issues that needed to be improved.

In addition, the above configuration requires two pipes, the sleeve 105 and the connecting pipe 106, and the pipes have different diameters, resulting in an increase in cost. Furthermore, the sleeve 105 and the connection pipe 106 are torch-brazed, which is time-consuming and causes a further cost increase. Therefore, it will be performed at a place near the heat exchanger main body. Therefore, as shown in FIG. 11, the heat of the torch brazing is absorbed by the heat exchanger main body portion composed of the end plate 103 and the plate fins 102 made of aluminum or the like, making it difficult to braze the sleeve 105 and the connecting pipe 106. As a result, there was also a problem that it was necessary to improve reliability by enabling reliable and strong brazing.

The present inventors discovered such a problem and came to constitute the subject matter of the present disclosure in order to solve the problem.

Therefore, the present disclosure solves the above problems and provides an inexpensive, high-performance, and highly reliable heat exchanger and a refrigeration system using the same.

Hereinafter, embodiments will be described in detail with reference to the drawings, taking the case of a laminated plate-fin heat exchanger as an example. However, more detailed description than necessary may be omitted. For example, detailed descriptions of well-known matters or redundant descriptions of substantially the same configurations may be omitted. This is to avoid the following description from becoming more redundant than necessary and to facilitate understanding by those skilled in the art.

It should be noted that the accompanying drawings and the following description are provided to allow those skilled in the art to fully understand the present disclosure and are not intended to limit the claimed subject matter thereby.

(Embodiment 1)
Embodiment 1 will be described below with reference to FIGS. 1 to 7. FIG.

[1-1. Constitution]
As shown in FIGS. 1 and 2, a plate fin laminate type heat exchanger (hereinafter simply referred to as a heat exchanger) 1 of the present embodiment has a plate fin laminate 2 in which strip-shaped plate fins 2a are laminated. end plates 3a and 3b having substantially the same shape in plan view are joined together to form a single unit. At the end thereof, there is a connecting pipe A4 which is an inlet when used as a condenser and an outlet when used as an evaporator, and a connecting pipe B5 which is vice versa. As shown in FIGS. 5 to 7, the connecting pipe A4 and the connecting pipe B5 are bending pipes bent in a substantially L-shape, and the connection structure thereof will be described in detail later.

The end plates 3a and 3b on both sides of the plate fin laminate 2 are brazed while sandwiching the plate fin laminate 2, and both ends in the longitudinal direction are connected and fixed by fastening means 7 to provide rigidity as a heat exchanger. holding

Further, as shown in FIG. 3, the plate fins 2a are configured such that a pair of plates 6a and 6b are joined by brazing or the like to have a heat transfer channel 8 through which a first fluid such as a coolant (hereinafter referred to as a coolant) flows. A number of plate fins 2a are laminated to form a lamination interval through which a second fluid such as air (hereinafter referred to as air) flows between the plate fins 2a. Heat is exchanged between the refrigerant flowing through the heat transfer passages 8 provided in the plate fins 2a and the air flowing through the gaps between the plate fins 2a.

The pair of plates 6a and 6b constituting the plate fins 2a has openings A9a and B10a for header flow passages serving as header flow passages A9 and B10 connected to the connection pipes A4 and B5, and the opening edges thereof. It has ring-shaped grooves 9b and 10b provided and a flow path forming groove 8a connecting the header flow path A9 and the header flow path B10. The pair of plates 6a and 6b are brazed to face each other to form the header flow path A9 and the header flow path B10, and the heat transfer flow path 8 connecting the header flow path A9 and the header flow path B10.

As shown in FIG. 4, the heat transfer flow path 8 is formed by folding back the other end of the heat transfer flow path 8 pulled out from one of the header flow paths A9, which serves as the entrance side, several times to form the other end side, which serves as the exit side. , and slits 11 are formed between adjacent flow paths to prevent heat transfer. Furthermore, the plate fins 2a of the plate fin laminate 2, which is formed by stacking the plate fins 2a having the above configuration, have a plurality of projections 12 (FIG. 3) appropriately provided along the longitudinal direction of the heat transfer flow paths 8 of the plate fins 2a. ) forms the lamination gap through which the air flows.

Next, the connection structure of the connecting pipes A4 and B5 in the heat exchanger 1 will be described with reference to FIGS. 5 to 7. FIG. Since the connection structure of the connection pipes A4 and B5 is the same, the connection pipe A4 will be described as an example.

The connection pipe A4 has a configuration in which a conventional sleeve and a connection pipe are integrated, and is formed in a substantially L shape as described above. As shown in FIG. 6, the connecting pipe A4 is provided with an expanded pipe portion 15 at the end of the end plate 3a on the side to be fitted into the opening 14 serving as a fluid inlet and outlet port, and a bead 16 formed on the outer peripheral portion thereof. The portion 15 is fitted into the opening 14, and the ring solder 17 interposed between the end plate 3a and the bead 16 is melted and joined by furnace brazing. Then, as shown in FIG. 5, a system pipe 18 on the refrigerating system side is joined to the other end of the connection pipe A4 by torch brazing.

The connection pipe A4, the end plate 3a, and the plate fins 2a are made of a metal having high thermal conductivity and light weight, such as aluminum or an aluminum alloy.

[1-2. motion]
Next, the effects of the plate-fin laminate type heat exchanger configured as described above will be described.

In the heat exchanger of the present embodiment, for example, when the heat exchanger is used under evaporation conditions, vapor-phase liquid refrigerant flows into the header flow path A9 on the inlet side of the plate-fin stack 2 from the connection pipe A4. The vapor-phase refrigerant that has flowed into the header channel A9 flows through the heat transfer channel 8 of each plate fin 2a, passes through the header channel B10 on the outlet side, and flows out from the connecting pipe B5 to the refrigerant circuit of the refrigeration system.

While flowing through the heat transfer passages 8, the gas-phase refrigerant exchanges heat with the air passing through the gaps between the plate fin stacks of the plate fin stack 2, and the vapor-phase refrigerant sequentially liquefies and flows out from the header flow passages B10.

In the heat exchanger 1 of this embodiment that operates in this manner, the connection pipe A4 is directly fitted into the opening 14 of the end plate 3a and joined. The protruding margin L can be reduced by the protruding dimension of the sleeve. As a result, the number of stacked plate fins 2a can be increased to increase the overall area of the heat exchanger 1 and improve the heat exchange performance.

In addition, since the end of the connection pipe A4 on the side of the connection to the heat exchanger is expanded, when the gas-liquid two-phase refrigerant flows into the heat exchanger 1 from the connection pipe A4, the flow velocity of the gas-liquid two-phase refrigerant is reduced. can be made As a result, when the heat exchanger 1 is installed so that the header flow path A9 is in a horizontal state, the inertial force of the gas-liquid two-phase refrigerant flowing into the header flow path A9 can be reduced. Separation of gas-phase refrigerant and liquid-phase refrigerant in the body portion is suppressed, and uneven distribution of refrigerant can be reduced, thereby improving heat exchange performance.

Further, by providing the expanded tube portion 15 in the connection pipe A4, a stepped portion 20 is formed between the expanded tube portion 15 and the small diameter portion 19 . Therefore, as shown in FIG. 7, a bead 16 can be formed by applying a compressive force to the expanded pipe portion 15 using the stepped portion 20 as a gripping margin, and the bead 16 can be easily formed even in a substantially L-shaped bent pipe. can be formed.

In addition, since the connecting pipe A4 is formed by integrating the sleeve of the conventional heat exchanger and the connecting pipe, it is possible to reduce the number of parts that cause an increase in cost, and at the same time, it is possible to reduce the number of parts that cause an increase in cost. Since the bead 16 is provided on the outer periphery of the portion 15, the ring brazing 17 can be interposed between the end plate 3a and the bead 16 for brazing in a furnace, thus making it possible to significantly reduce the number of brazing man-hours. .

At this time, if the heat exchanger 1 is installed horizontally, that is, if the plate fins 2a are installed vertically as shown in FIG. The ring wax 17 is melted between the rim of the opening 14 and solidifies around the outer circumference of the pipe substantially evenly due to its surface tension. Therefore, the outer periphery of the connecting pipe A4 can be uniformly joined to the opening 14 of the end plate 3a with brazing material, and the joint can be made reliable and strong. Further, since the plate fins 2a are oriented vertically, it is possible to prevent deformation due to the weight of the plate fins themselves, which is a concern when the surfaces of the plate fins 2a are oriented horizontally.

On the other hand, the system pipe 18 is joined to the opposite end of the connection pipe A4 by torch brazing. Torch brazing is performed at a location far away from the main body of the exchanger. Therefore, it is possible to suppress the heat of the torch brazing from being absorbed by the heat exchanger main body portion, so that reliable brazing is possible.

[1-3. effects, etc.]
As described above, the laminated plate-fin heat exchanger of the present disclosure includes an end plate 3a having an opening 14 serving as an inlet/outlet for fluid, and a connecting pipe A4 connected to the opening 14 of the end plate 3a. The connection pipe A4 is formed of a bent pipe, and an expanded pipe portion 15 with a bead 16 is provided on the opening 14 side of the end plate 3a, and the expanded pipe portion 15 is fitted and joined to the opening 14 of the end plate 3a. and

As a result, the protruding margin of the connecting pipe A4 can be reduced to increase the overall area of the heat exchanger, and the fluid distribution in the heat exchanger can be made more uniform due to the effect of slowing down the flow velocity of the expanded tube. and the heat exchange performance can be improved. Moreover, the joining of the connecting pipe A4 to the end plate 3a can be performed by furnace brazing, and the torch brazing of the system pipe 18 to the connecting pipe A4 can be performed at a distance from the main body of the heat exchanger. It is possible to make brazing with high reliability. In addition, cost increases can be suppressed by reducing the number of parts and reducing the man-hours for brazing by brazing in a furnace. Therefore, it is possible to provide an inexpensive, high-performance, and highly reliable heat exchanger and a refrigeration system using the same.

(Embodiment 2)
Embodiment 2 will be described below with reference to FIGS. 8 and 9. FIG.

[2-1. Constitution]
FIG. 8 is a refrigeration cycle diagram of an air conditioner configured using the heat exchanger according to Embodiment 1, and FIG. 9 is a schematic cross-sectional view showing an indoor unit of the air conditioner.

8 and 9, this air conditioner is composed of an outdoor unit 51 and an indoor unit 52 connected to the outdoor unit 51. As shown in FIG. The outdoor unit 51 includes a compressor 53 that compresses the refrigerant, a four-way valve 54 that switches the refrigerant circuit during cooling and heating operation, an outdoor heat exchanger 55 that exchanges heat between the refrigerant and the outside air, a pressure reducer 56 that reduces the pressure of the refrigerant, and an outdoor unit. A blower 59 is provided. Further, the indoor unit 52 is provided with an indoor heat exchanger 57 for exchanging heat between the refrigerant and indoor air, and an indoor fan 58 . Then, the plate fin laminated heat exchanger exemplified in Embodiment 1 is used as the indoor heat exchanger 57, and the compressor 53, the four-way valve 54, the indoor heat exchanger 57, the pressure reducer 56, and the outdoor heat exchanger 55 are used. They are connected by a refrigerant circuit to form a heat pump refrigeration cycle.

[2-2. motion]
The air conditioner configured as described above switches the four-way valve 54 so that the discharge side of the compressor 53 and the outdoor heat exchanger 55 communicate with each other during the cooling operation. As a result, the refrigerant compressed by the compressor 53 becomes a high-temperature, high-pressure vapor-phase refrigerant and is sent to the outdoor heat exchanger 55 through the four-way valve 54 . Then, the refrigerant exchanges heat with the outside air, radiates heat, becomes a high-pressure liquid-phase refrigerant, and is sent to the pressure reducer 56 . In the decompressor 56 , the refrigerant is decompressed into a low-temperature, low-pressure two-phase refrigerant, which is sent to the indoor unit 52 . In the indoor unit 52, the refrigerant enters the indoor heat exchanger 57, exchanges heat with the indoor air, absorbs heat, evaporates, and becomes a low-temperature gas refrigerant. At this time, the indoor air is cooled to cool the room. Further, the refrigerant returns to the outdoor unit 51 and is returned to the compressor 53 via the four-way valve 54 .

On the other hand, during heating operation, the four-way valve 54 is switched so that the discharge side of the compressor 53 and the indoor unit 52 are communicated. As a result, the refrigerant compressed by the compressor 53 becomes a high-temperature, high-pressure refrigerant, passes through the four-way valve 54 , and is sent to the indoor unit 52 . The high-temperature and high-pressure refrigerant enters the indoor heat exchanger 57, exchanges heat with the indoor air, radiates heat, and is cooled to become a high-pressure liquid refrigerant. At this time, the indoor air is heated to heat the room. After that, the refrigerant is sent to the pressure reducer 56, is decompressed in the pressure reducer 56 to become a low-temperature low-pressure two-phase refrigerant, is sent to the outdoor heat exchanger 55, exchanges heat with the outside air, evaporates, and passes through the four-way valve 54. and returned to the compressor 53.

[2-3. effects, etc.]
Since the refrigerating system of the present disclosure uses the heat exchanger shown in the first embodiment as the indoor heat exchanger 57, the refrigerating system can be inexpensive, highly efficient, and highly reliable.

[Other embodiments]
As described above, the heat exchanger according to the present invention and the refrigeration system using the same have been described using the above-described embodiment, but the present invention is not limited to this, and various modifications, replacements, additions, omissions can be made. etc. can be done. For example, the heat exchanger is not limited to a plate-fin laminate type heat exchanger, and any heat exchanger having a similar structure may be used. Also, although the first fluid is the coolant and the second fluid is air, the present invention is not limited to this. Further, although an air conditioner is exemplified as the refrigeration system, a heat pump water heater using water as the second fluid may be used. In other words, the embodiments disclosed this time are illustrative in all points and are not restrictive, and the scope of the present invention is indicated by the claims, and within the meaning and scope equivalent to the claims All changes are included.

INDUSTRIAL APPLICABILITY As is clear from the description of the above embodiments, the present invention can provide an inexpensive, highly reliable, high-performance heat exchanger and a refrigeration system using the same. Therefore, it can be widely used for heat exchangers used in domestic and commercial air conditioners, heat pump water heaters, etc., and various refrigerating equipment, and has great industrial value.

REFERENCE SIGNS LIST 1 heat exchanger 2 plate fin laminate 2a plate fins 3a, 3b end plates 4 connection pipe A
5 Connection pipe B
6a plate 6b plate 7 fastening means (bolts and nuts)
8 heat transfer channel 8a channel forming concave groove 8b heat transfer channel lead-out portion 9 header channel A
10 header channel B
10a heat transfer flow path lead-out portion 11 slit 12 projection 14 opening 15 tube expansion portion 16 bead 17 ring row 18 system pipe 19 small diameter portion 20 stepped portion 51 outdoor unit 52 indoor unit 53 compressor 54 four-way valve 55 outdoor heat exchanger 56 pressure reducer 57 indoor Heat exchanger 58 Indoor fan 59 Outdoor fan

Claims (2)

An end plate having an opening serving as an entrance and exit for a fluid, and a connection pipe connected to the opening of the end plate, the connection pipe being formed of a bent pipe, and an expanded pipe portion having a bead on the opening side of the end plate. is provided, and the expanded tube portion is fitted into the opening of the end plate and joined. A refrigeration system in which the heat exchanger according to claim 1 is used as a heat exchanger that constitutes a refrigeration cycle.

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